1. Technical Field of the Invention
This invention relates generally to network interfaces such as an Ethernet interface devices.
2. Description of Related Art
Energy costs continue to escalate in a trend that has accelerated in recent years. Such being the case, various industries have become increasingly sensitive to the impact of those rising costs. One area that has drawn increasing scrutiny is the IT infrastructure. Many companies are now looking at their IT systems' power usage to determine whether the energy costs can be reduced. For this reason, an industry focus on energy efficient networks has arisen to address the rising costs of IT equipment usage as a whole (i.e., PCs, displays, printers, servers, network equipment, etc.).
In designing an energy efficient solution, one of the considerations is the utilization of the network link. For example, many network links are typically in an idle state between sporadic bursts of data. The transmission of idle signals on a link wastes energy and adds to the radiated emission levels. Identification of these frequent low link utilization periods can therefore provide opportunities to produce energy savings.
The IEEE standard 802.3az (10GBASE-T) provides a low power idle (LPI) mode of operation. An energy efficiency control policy in a network device is operative to analyze the link utilization to determine whether to enter the LPI mode to save power. In this mode of operation, refresh signals are transmitted periodically in order to maintain the link and facilitate the resumption of the link at high speeds when data transfer recommences.
The disadvantages of conventional approaches will be evident to one skilled in the art when presented the disclosure that follows.